The proposed scoring system has the potential to increase equity in organ transplantation, increase transplantation rates, and improve patient survival rates

The system, devised by researchers at Case Western Reserve University and the Cleveland Clinic, better accounts for the biological shortcomings that limit some patients' access to transplants.

Researchers at Case Western Reserve University and the Cleveland Clinic have developed a new method that could provide better access to lung transplants for transplant candidates who are difficult to match due to blood type or height.

Analysis published in Heart and Lung Transplant Journal demonstrate significant inequalities in access to lung transplantation based on these candidate characteristics and suggest ways to address them.

Lung transplant candidates require an organ from a donor of similar height and compatible blood type. Currently, in the United States, the lung allocation system ranks candidates using a composite allocation score that includes a biological disadvantage subscore to ensure that candidates with the same disease have equal access to transplants. . This subscore gives additional points to people who are short and have difficult to match blood types.

Researchers at Case Western Reserve University and the Cleveland Clinic analyzed data from adult lung transplant candidates and donors across the United States to determine alternative scoring for blood type and height components of the biological disadvantage subscore of the composite allocation score.・Developed the system. This approach predicts the supply of organs that are compatible with a particular candidate based on a combination of individual characteristics. The team then used a new, recently developed and validated simulation model to assess the expected impact of implementing the proposed solution on U.S. patients on the lung transplant waiting list. I did.

While current composite allocation scores consider the effects of blood type and height independently, the researchers' approach, which considers blood type and height-based disparities simultaneously, allows candidates to choose these biological characteristics as an option. may have in combination with, thus providing a more comprehensive assessment of biological disadvantage.

“This approach could reduce mortality on the organ waiting list,” said Mariam Varapour, a pulmonologist at the Cleveland Clinic and co-senior author of the study with Jarrod Dalton, an associate professor at the Cleveland Clinic Lerner School of Medicine. “This has the potential to reduce the overall transplantation rate and increase the overall transplantation rate.” Case Western Reserve.

“It also further reduces the biological disadvantage caused by difficult-to-match blood type and height combinations,” Dalton says.

Disadvantages due to the fact that candidates with type O blood can only accept organs from type O donors, whereas type O organs are compatible with any ABO blood type candidate. face. An analysis that adjusted for height and patient medical urgency found that type O candidates had a 37% lower transplant rate than type A candidates under the current system.

The height difference between donor and candidate is also an important factor to consider when considering the surgical feasibility in lung transplantation. The relationship between height of lung transplant candidates and waiting list outcomes is well established and reflects the relative scarcity of very tall or very short donors. For example, candidates who are 5'9″ tall are 61% more likely to receive a transplant compared to candidates who are 5'3″ tall.

“This is a central mechanism for the long-observed sex differences in lung transplantation. Women tend to be shorter than men; for example, 25% of women are under 5 feet 3 inches tall. “Compared to only 1% of men,” he said. Varapur.

“While recent policy changes and debates have focused on disparities based on blood type, our analysis shows that extreme height is likely to have greater disadvantages than previously understood and that the current It shows that the system is not adequately addressing this,” Associate Professor Johnny Rose said. Professor of Medicine and co-lead author of the study.

“Addressing policies related to blood type and height-related disparities will help move us closer to achieving equitable access to lung transplants in the United States,” Varapour said.

The researchers then work to optimize the weights given to the components of the biologically disadvantaged composite allocation score. Ultimately, this approach could be applied to other transplant organ allocations.

This project received funding from the National Heart, Lung, and Blood Institute of the National Institutes of Health (R01HL153175).

For more information, please contact Patty Zamora at patty.zamora@case.edu.